Calycanthus are deciduous shrubs that are commonly grown as ornamental landscape plants. There are three species of Calycanthus. Calycanthus floridus (common sweetshrub, Carolina allspice, Carolina sweetshrub, strawberry-shrub, bubby blossom, sweet bubby, sweet Bettie, spicebush) is found throughout much of the Eastern United States and commonly grows as an understory shrub in mixed deciduous forests, often along streams and in moist woodlands. Plant height can vary and ranges from 1 to 2.5 meters, growing as multi-stemmed shrubs with suckering shoots arising from the base and roots. Fall color can be an attractive buttery yellow. The flowers range in size (2-3 cm across) with tepals that vary from reddish purple to a dark chocolate brown. The fragrance is variable, but can have a pleasant fruity aroma. Older synonyms for this species include Calycanthus glaucus, C. fertilis, C. floridus var. laevigatus, C. floridus var. oblongifolius, C. nanus, C. brockianus, and C. mohrii. 
Calycanthus occidentalis (California sweetshrub) is naturally found in Washington and California growing as an understory species along streams and on moist canyon slopes. Although similar to the Carolina sweetshrub, the California species is larger in almost all respects with the plants growing to over 3.5 meters tall. The flowers, although slightly larger (2 to 4 cm across) and a brighter red, are typically not as fragrant as those produced by C. floridus. 
The Chinese wax shrub Calycanthus chinensis (Sinocalycanthus chinensis) is a rare species native to the Zheijang Province in southeast China. This medium-sized shrub grows to 1 to 2.7 meters tall with large, glossy leaves. The flowers open more completely (up to 8 cm in diameter) than do North American species and are multicolored with the outer perianth whorl being whitish pink and the inner whorl being a strong yellow with occasional purple streaks at the base, with no fragrance.
Calycanthus is becoming increasingly popular as a landscape plant for use as a shrub border, foundation plant or a naturalizing plant. Calycanthus has few disease or insect pest problems. Several horticultural varieties of Calycanthus floridus are known including ‘Athens’ (unpatented), ‘Edith Wilder’ (unpatented), and ‘Michael Linsey’ (unpatented). As far as the inventors are aware, no varieties of Calycanthus are patented.
The present invention relates to a new and distinct hybrid variety of Calycanthus which is known botanically as Calycanthus L. ‘Venus’ (×Sinocalycalycanthus ‘Venus’ Lasseigne and Fantz) and has been given the cultivar name ‘Venus’. Calycanthus ‘Venus’ is suitable for use as a medium-sized ornamental landscape shrub.
There is some disagreement about the classification of the Chinese wax shrub. Some consider that the proper classification is in the genus Calycanthus (i.e., Calycanthus chinensis, W. C. Cheng and S. Y. Chang); but another treatment places it in a separate genus (Sinocalycanthus chinensis, W. C. Cheng and S. Y. Chang). However, recent molecular phylogeny data (Zhou, S., S. Renner, and J. Wen. Molecular phylogeny and inter and intracontinental biogeography of Calycanthaceae. In Preparation) has indicated that this species is genetically embedded among other Calycanthus species providing strong justification to place the Asian species within the genus Calycanthus. Based on this treatment, the proper scientific name for the hybrid of the invention is: Calycanthus L. ‘Venus’. If future taxonomic treatments place the Chinese wax shrub into the genus Sinocalycanthus, then the proper scientific name for this new hybrid would be: ×Sinocalycalycanthus Lasseigne and Fantz ‘Venus’.
Parentage. Calycanthus cultivar ‘Venus’ resulted from controlled pollinations using three different species (female parents are listed first for each combination; see FIG. 4):H2000-14-001 (Calycanthus chinensis×Calycanthus floridus ‘Athens’) [unpatented]×H2000-17-002 (Calycanthus chinensis×Calycanthus occidentalis) [unpatented].
Calycanthus ‘Venus’ originated from a controlled breeding program, and was selected from seed germinated in the Fall of 2001 in a cultivated area at the North Carolina State University, Mountain Horticultural Crops Research Station, Fletcher, N.C., USA.
Asexual reproduction. The first asexual propagation of ‘Venus’ was carried out in June, 2002 by rooting stem cuttings at North Carolina State University, Mountain Horticultural Crops Research Station, Fletcher, N.C., USA. Calycanthus cultivar ‘Venus’ roots readily (>90%) from firm, subterminal, softwood cuttings when treated with a basal dip of 5,000-10,000 ppm indole butyric acid (potassium salt) in water. The combination of distinguishing characteristics disclosed herein for ‘Venus’ have remained stable and true to type through successive cycles of asexual propagation.